Arsenic Drinking Water Standard Pending Revision

Less than three months after the January 2006 deadline for public water systems to make operational changes to comply with the 10 ppb MCL for arsenic, the U.S. EPA is proposing a revision. The revision would allow systems serving 10,000 or fewer residents to have as much as 30 ppb of arsenic, three times the level of contaminants allowed under the new regulations.

The proposed revision is a direct response to complaints by small communities that cannot afford to comply with the new limit.

According to the EPA, about 10 million Americans are drinking water that does not meet the new federal standards for arsenic. Currently, about 50 million people live in communities that would be affected by the proposed change.

In an interview with The Washington Post, Benjamin H. Grumbles, assistant administrator for EPA’s Office of Water, said the agency was trying to satisfy Congress, which in 1996, instructed the EPA to take into account that it costs small rural towns proportionately more to meet federal drinking water standards. According to Grumbles, both public health protection and affordability can be achieved.

Under the Safe Drinking Water Act Amendments of 1996, the cost to comply with federal drinking water standards should not exceed more than 2.5% of the median U.S. household income, which in 2004 was $44,684, thus, complying should not cost more than $1,117 per household.

EPA’s proposal would result in a compliance cost limit of $335 per household.

Some public officials and environmental experts told The Washington Post they worry the proposal could lead to broad exemptions from the current federal contaminant standards cities and larger towns must also meet.
The Association of State Drinking Water Administrators Executive Director James Taft said he and others are concerned that the less stringent standard will “become the rule, rather than the exception” if larger communities press for similar relief.

Rep. Henry A. Waxman (D-Calif.), who helped write the 1996 law, said EPA’s proposal, “if finalized, would allow weakened drinking water standards, not just in rural areas, but in the majority of drinking water systems in the U.S.”

On the other hand, Sen. Pete Domenici (R-N.M.) said he supports a reconsideration of EPA’s arsenic drinking water standard, particularly in light of additional scientific information that calls into question the necessity to limit contaminants to 10 ppb.

Recently, Domenici opened a briefing hosted by the National Rural Water Association to review the implementation impact of the EPA arsenic standard, which also reviewed a study published in March in the National Institutes of Health’s scientific journal, Environmental Health Perspectives. According to Domenici, there is a significant step between the 100 ppb level cited as safe in this study and the imposed 10-ppb standard.

“With the science on which EPA based the new standards coming under credible question, I surely support EPA’s serious reconsideration of the new standard,” Domenici said. The senator has long been critical of the scientific basis for the 10-ppb arsenic standard, particularly because arsenic is a naturally occurring element in New Mexico.

The proposed revision was revealed in early March in the Federal Register, and public comments were accepted until May 1.